import java.util.HashMap;
import java.util.HashSet;
import java.util.Scanner;
import java.util.Stack;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: COFFEEWEN
 * Date: 2022-10-24
 * Time: 18:32
 */
public class Test {
    public static void main1(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while(scanner.hasNext()){
            int ret = scanner.nextInt();
            int f0 = 0;//1
            int f1 = 1;//1
            int f2 = f0+f1;
            while(ret > f2){
                f0 = f1;
                f1=  f2;
                f2 = f1+f0;
            }
            if(Math.abs(ret - f1) < Math.abs(ret - f2)){
                System.out.println(Math.abs(ret - f1));
            }else {
                System.out.println(Math.abs(ret - f2));
            }
        }
    }
    public static void main(String[] args) {
        /*Scanner scanner = new Scanner(System.in);
        while(scanner.hasNextLine()){
            String str = scanner.nextLine();
            HashSet<String> set = new HashSet<>();
           String[] s =  str.split(" ");
           int ct = 0;
            for(String t : s){
                set.add(t);
            }
            System.out.println(set.size());
        }*/
        Stack<String> stack = new Stack<String>();
        stack.push("4");
        stack.push("5");
        System.out.println(stack.pop());
        System.out.println(stack.isEmpty());
    }
}
